1. Field of the Invention
This invention relates to gate valves used in machine shops that serve to control the flow of suction in collecting sawdust, mill filings and the like as well as mist and fume collection and more particularly to an advanced electric gate valve and accompanying system allowing the efficient operation of vacuum collection of dust and filings resulting in significant energy savings and noise reduction.
2. Description of the Related Art
The entirety of U.S. Pat. No. 6,012,199 issued Jan. 11, 2000 is incorporated herein by this reference thereto.
In machine shops, woodworking shops, and the like, work pieces are milled, lathed, drilled, formed, etc. to achieve the ends of the craft. In altering the structure of the work piece, dust, filings and/or tailings are created. For example, when sawing a piece of wood, sawdust will collect adjacent the area of the saw blade. Likewise, for lathing or milling processes, shavings or tailings from the metal work piece about or below the cutting blade.
Additionally, fumes or mist may be generated during industrial production, such as the lead fumes generated during the production of different types of batteries. Such fumes can be harmful to exposed workers and toxic to the environment.
The sawdust and/or metal shavings that collect in the workshop can become dangerous. The dust or micro fine metal particles may become airborne and inhaled deeply into the lungs of persons in the general vicinity, possibly causing injury and/or disease. Additionally, thick suspensions of dust become fire or explosion hazards as an explosion or fire may occur if the dust comes into contact with a spark or flame. Consequently, it is of great interest both to the proprietor and to the persons working in the shop to minimize the hazards arising from collection and suspension of dust and the like, including fumes and mist. Likewise, governmental regulations (OSHA or otherwise) may impose similar safety requirements.
Prior attempts to eliminate sawdust, metal shavings, and the like from the machine shop work area have used a centralized vacuum system where a central vacuum motor pulls a vacuum through a series of ducts. The end of the ducts are open adjacent the machine areas where dust or wood collect. The dust then travels through the ductwork to a collection or storage bin that is emptied on a periodic basis. Currently, in furtherance of the art, gates controlling the flow of air through the ductwork may be used so that a vacuum or suction is only pulled in areas where actual work is being done which reduces the necessary power needed to drive the dust-collecting vacuum system. This eliminates the energy waste associated with the vacuuming of otherwise clean and dust free areas. It also reduces the load the vacuum has to pull.
Currently, blast gates are known in the art and are generally controlled pneumatically. These gates are generally expensive and use a number of moving parts. Additionally, such blast gates and their hydraulic lines may be difficult to install, often requiring a professional. Such expense and difficulty may prevent their installation in smaller workshop areas where the initial cost may outstrip the monies available to pay for such a safety system.
Automatic control of such blast gates is preferred to manual operation as it is most the most efficient and convenient. While the preferred placement of blast gates is as close to the dust-creating machinery as possible, automatic blast gates also enable the spacing of the blast gates away from a flexible end of the duct so that it may have as much freedom as possible to operate, flexing under manual control to collect available dust, etc. or to be easily fixed in an advantageous dust-collecting position relative to a machine. Additionally, with manual gates, the operator must manually operate each of the gates for each of the machines. Gates that are left open when the associated machine is not being used are noisy and waste energy. Without the use of blast gates, the central dust collector must be much larger as the effective vacuum it must pull must match that necessary for every machine and every open duct all the time.
Alternatively, fumes and mist may arise from industrial processes such as occurs during the production of batteries (which may produce lead fumes). Such fumes and mist require collection to reduce toxicity and protect workers. Collection techniques for dust and particles can be applied to fume and mist collection.
Consequently, it is to some advantage to provide an inexpensive vacuum system using a simple and effective blast gate that is self-cleaning and provides automatic response to the operation of a machine for which dust needs collection. Such an automatic response may include the collection and implementation of instantaneous air-volume needs. Such a system may use a simple, easy to manufacture, and easy to maintain blast gate that is signaled by a central processor. The central processor may receive signals from a sensor that detects whether or not a machine associated with the sensor is in operation and therefore whether or not dust should be collected at that location. The central processor may also adjust gate operation to provide minimal necessary levels of air velocity and volume. Such a system may provide both energy-efficient operation, as well as noise reduction, respectively reducing costs and providing a more comfortable sonic environment.
In the present invention, a minimum required level of air velocity and airflow is maintained due to operational requirements. The associated computer may adjust the blast gates so that a minimal percentage of gates are open or a sufficient open cross section is maintained to maintain minimum air volume passage through the ducting system. The vacuum to system may be designed by using calculations based on the probability of machine use as well as general system ducting described in more detail herein. For increased efficiency or otherwise, smaller duct work cross sections may be used in certain applications or subsystems of the present invention. The vacuum system set forth herein may not only be used in word working and machining facilities, but also in printing, food processing, chemical, mining, car manufacturing or other manufacturing, medical facilities, as well as other factories and plants.
The invention described in the foregoing description and accompanying claim remedies many of the drawbacks presently exhibited by machine shop dust collection systems and does so in an inexpensive and highly-effective manner.